class Maybe {
    static of(value) {
        return new Maybe(value)
    }

    constructor(value) {
        this._value = value
    }
    map(fn) {
        return this.isNothing(this._value) ? Maybe.of(null) : Maybe.of(fn(this._value))
    }
    isNothing(value) {
        return value === null || value === undefined
    }
}



class Container {
    static of(value) {
        return new Container(value)
    }

    constructor(value) {
        this._value = value
    }
    map(fn) {
        return this.isNothing(this._value) ? Container.of(null) : Container.of(fn(this._value))
    }
    isNothing(value) {
        return value === null || value === undefined
    }
}


module.exports = {
    Maybe,
    Container
}